This invention relates to the signal processing associated with fault tolerant multiple sensor signals, and more particularly, to multiple torque sensor reasonableness diagnostics to ensure fault tolerance.
Many control systems employ multiple sensors to achieve some level of fault tolerance. In some systems, two sensors are employed, providing confidence that if a sensor fails response to the failed sensors may be controlled in a deterministic manner. Under such conditions, continued operation may not be possible, but at least the response to a loss of a sensor may be constrained. In other systems, three or more sensors may be employed to provide complete redundancy, and thereby providing some level of tolerance to a particularized fault as voting among the sensors and their inputs may now be accomplished.
However, additional sensors inherently require additional integration packaging, complexity, and interface signal processing, all of which add cost. Therefore, it would be beneficial to provide deterministic fault tolerance while employing a minimum of redundant sensors and signal processing interfaces.